Social links page with HTML and CSS

Your solution is very similar to the original design, congrats! I'm a beginner, but I think I could give you some suggestions:

• Your responsive layout works well, but would help using (%, rem, em) instead of px to get a better responsive feedback.
• This suggestion I got from my course monitor: Inside the <nav>, seeing that it's a group of links, you could use the tag <ul><li> for better semantic. Furthermore, there was no need for <button> because it's a link and already used the <a>. -- So, it could be like that:

<nav>
      <ul>
            <li><a href="#">GitHub</a></li>
            <li><a href="#">Frontend Mentor</a></li>
            <li><a href="#">LinkedIn</a></li>
            <li><a href="#">Twitter</a></li>
            <li><a href="#">Instagram</a></li>
      </ul>
</nav>